Officials say the Trump administration is planning to ban American citizens from travelling to North Korea after the death of Otto Warmbrier, who died after falling into coma in a North Korean prison.

Image shows Otto Warmbier being brought to North Korean court. The 22 year-old American student lost his life after getting into a coma in North Korean Prison.

US officials say the Trump administration will ban American citizens from travelling to North Korea following the death of university student Otto Warmbier who passed away after falling into coma in a North Korean prison.

The officials said Friday that Secretary of State Rex Tillerson had decided to impose "geographic travel restriction" to North Korea, which would make the use of US passports to enter the country illegal.

They said the restriction would go into effect 30 days after a notice is published in the Federal Register, but it was not immediately clear when that would be.

There was no announcement in Friday's editions of the government publication. The officials were not authorised to publicly discuss the decision before it is announced and spoke on condition of anonymity.

Two tour operators that organise group trips to North Korea said they had already been informed of the decision.

Restricted travel is not a new phenomena

Under US law, the secretary of state has the authority to designate passports as restricted for travel to countries with which the United States is at war, when armed hostilities are in progress, or when there is imminent danger to the public health or physical security of United States travellers.

Geographic travel restrictions are rare but have been used by numerous administrations in the past for countries where it has been determined to be unsafe.

Since 1967, such bans have been imposed intermittently on countries such as Algeria, Iraq, Lebanon, Libya, Sudan, Cuba and North Vietnam.

Warmbier's death triggered the ban

In this case, the administration had been considering the step since Warmbier died after being medically evacuated in a coma from North Korea last month.

Warmbier suffered a severe neurological injury from an unknown cause while in custody.

Relatives said they were told the 22-year-old University of Virginia student had been in a coma since shortly after he was sentenced to 15 years of hard labour in North Korea in March 2016.

He had been accused of stealing a propaganda poster while on a tour of the country.

The United States, South Korea and others often accuse North Korea of using foreign detainees to wrest diplomatic concessions. At least three other Americans remain in custody in the North.